Intestinal Protein Characterisation of SARS-CoV-2 Entry Molecules ACE2 and TMPRSS2 in Inflammatory Bowel Disease (IBD) and Fatal COVID-19 Infection.

The coronavirus SARS-CoV-2 contributes to morbidity and mortality mainly as a result of immune-pathology in the lungs. Recent data has shown multi-system involvement with widespread viral tropism. Here we present a detailed intestinal protein characterisation of SARS-Cov-2 entry molecules ACE2 and TMPRSS2 in patients with inflammatory bowel disease ([IBD]; ulcerative colitis [UC] and Crohn's disease [CD]) with age- and sex-matched non-IBD controls, and in those with fatal COVID-19 infection. In our dataset, ACE2 and TMPRSS2 displayed a membrane enterocyte staining in the ileum (due to presence of brush border/microvilli) in contrast to a cytoplasmic pattern in the colon. We also showed a high ACE2/low TMPRSS2 expression pattern in the ileum with a reverse trend in the colon. In UC, colonic ACE2 and TMPRSS2 are cytoplasmic in nature, with significantly higher ACE2 staining intensity compared to non-IBD controls. In inflamed and unaffected IBD mucosa, ileal and colonic enterocyte ACE2 and TMPRSS2 expressions are not modified in the histologic presence of inflammation. We observed immune cells within the lamina propria that expressed ACE2 and TMPRSS2, at higher frequencies in IBD when compared to non-IBD controls. These were identified as plasma cells with multiple myeloma oncogene 1/interferon regulatory factor 4 (MUM1/IRF4) expression. We further analysed the gut histology of six fatal COVID-19 cases, with no difference in colonic and ileal ACE2/TMRPSS2 staining (compared to non-IBD controls) and identified ACE2 + lamina propria plasma cells. Of interest, in this COVID-19 cohort, there was no histologic evidence gut inflammation despite known evidence of viral tropism within the enterocytes. Our data provides evidence for tissue expression of entry molecules ACE2 and TMPRSS2 including a close apposition to plasma cells - both pointing towards a role of the gut in the antecedent immune response to SARS-CoV-2 infection.

Determining the prognostic significance of IKKα in prostate cancer.

BACKGROUND: As the survival of castration-resistant prostate cancer (CRPC) remains poor, and the nuclear factor-κB (NF-κB) pathways play key roles in prostate cancer (PC) progression, several studies have focused on inhibiting the NF-κB pathway through generating inhibitory κB kinase subunit α (IKKα) small molecule inhibitors. However, the identification of prognostic markers able to discriminate which patients could benefit from IKKα inhibitors is urgently required. The present study investigated the prognostic value of IKKα, IKKα phosphorylated at serine 180 (p-IKKα S180) and threonine 23 (p-IKKα T23), and their relationship with the androgen receptor (AR) and Ki67 proliferation index to predict patient outcome. METHODS: A cohort of 115 patients with hormone-naïve PC (HNPC) and CRPC specimens available were used to assess tumor cell expression of proteins within both the cytoplasm and the nucleus by immunohistochemistry. The expression levels were dichotomized (low vs high) to determine the associations between IKKα, AR, Ki67, and patients'Isurvival. In addition, an analysis was performed to assess potential IKKα associations with clinicopathological and inflammatory features, and potential IKKα correlations with other cancer pathways essential for CRPC growth. RESULTS: High levels of cytoplasmic IKKα were associated with a higher cancer-specific survival in HNPC patients with low AR expression (hazards ratio [HR], 0.33; 95% confidence interval [CI] log-rank, 0.11-0.98; P = .04). Furthermore, nuclear IKKα (HR, 2.60; 95% CI, 1.27-5.33; P = .01) and cytoplasmic p-IKKα S180 (HR, 2.10; 95% CI, 1.17-3.76; P = .01) were associated with a lower time to death from recurrence in patients with CRPC. In addition, high IKKα expression was associated with high levels of T-cells (CD3+ P = .01 and CD8+ P = .03) in HNPC; however, under castration conditions, high IKKα expression was associated with high levels of CD68+ macrophages (P = .04), higher Gleason score (P = .01) and more prostate-specific antigen concentration (P = .03). Finally, we identified crosstalk between IKKα and members of the canonical NF-κB pathway in the nucleus of HNPC. Otherwise, IKKα phosphorylated by noncanonical NF-κB and Akt pathways correlated with members of the canonical NF-κB pathway in CRPC. CONCLUSION: The present study reports that patients with CRPC expressing high levels of nuclear IKKα or cytoplasmic p-IKKα S180, which associated with a lower time to death from recurrence, may benefit from IKKα inhibitors.

Androgen receptor phosphorylation at serine 81 and serine 213 in castrate-resistant prostate cancer.

BACKGROUND: Despite increases in diagnostics and effective treatments, over 300,000 men die from prostate cancer highlighting the need for specific and differentiating biomarkers. AR phosphorylation associates with castrate-resistance, with pARser213 promoting transcriptional activity. We hypothesise that combined pARser81 and pARser213 reduces survival and would benefit from dual-targeting androgen-dependent and Akt-driven disease. METHODS: Immunohistochemistry and immunofluorescence were performed on matched hormone-naive and castrate-resistant prostate cancer samples. TempO-Seq gene profiling was analysed using DESeq2 package. LNCaP-AI cells were stimulated with DHT or EGF. WST-1 assays were performed to determine effects of Enzalutamide and BKM120 on cell viability. RESULTS: Following the development of castrate-resistance, pARser81 expression reduced and pARser213 expression increased. Castrate-resistance pARser81 expression was not associated with survival but high pARser213 expression was associated with reduced survival from relapse. Combined high pARser81 and pARser213 was associated with reduced survival from relapse. pARser81 expression was induced by 10 nM DHT or 10 nM EGF and pARser213 expression was induced by treatment with 10 nM EGF in LNCaP-AI cells. Cell viability was reduced following treatment with 10 nM Enzalutamide and 10 nM BKM120. Eight genes were differentially expressed between hormone-naive and castrate-resistant tumours and twenty-five genes were differentially expressed between castrate-resistant tumours with high and low pARser213 expression. CONCLUSION: Combined pARser81 and pARser213 provides a novel prognostic biomarker for castrate-resistant disease and a potential predictive and therapeutic target for prostate cancer. Further studies will be required to investigate the combined effects of targeting AR and PI3K/AKT signalling.

A review on the interactions between the tumor microenvironment and androgen receptor signaling in prostate cancer.

Prostate cancer growth is controlled by androgen receptor signaling via both androgen-dependent and androgen-independent pathways. Furthermore, the prostate is an immune competent organ with inflammatory changes both within the systemic and local environment contributing to the reprogramming of the prostatic epithelium with consistently elevated lymphocyte infiltration and proinflammatory cytokines being found in prostate cancer. The crosstalk between the tumor microenvironment and androgen receptor signaling is complex with both protumorigenic and antitumorigenic roles observed. However, despite an increase in immune checkpoint inhibitors and inflammatory signaling blockades available for a range of cancer types, we are yet to see substantial progress in the treatment of prostate cancer. Therefore, this review aims to summarize the tumor microenvironment and its impact on androgen receptor signaling in prostate cancer.